SIRE EVALUATION

Associations among sire and maternal grandsire evaluations for calving difficulty and calf mortality were investigated in the Israeli Holstein population. Primiparous and multiparous calvings were analysed separately. Genetic correlations between calving difficulty and calf mortality were close to unity for primiparous calvings but lower for multiparous calvings. Genetic correlations between primiparous and multiparous sire evaluations were .94 and .72 for calving difficulty and calf mortality. Genetic correlations between sire and maternal grandsire evaluations were .6 for primiparous calvings and not-significant for multiparous calvings for both traits. These results correspond to findings that the direct genetic effect is larger than the maternal effect but that there is a slight negative correlation between them. We suggest that sire evaluations for calving difficulty of multiparous cows be used as a preliminary prediction of heifer calving difficulty and calf mortality and that...

Esta Evaluación de Sementales 2014 es el resultado del análisis de la información del
ganado registrado en la Asociación Mexicana de Criadores de Ganado Santa
Gertrudis, A.C.
La Diferencia Esperada en la Progenie (DEP) es el mejor estimador del valor genético
de un animal que se tiene en la actualidad. Las investigaciones han mostrado que las
DEPs representan la herramienta disponible más precisa para mejorar genéticamente
una característica. Las DEPs y la información que las acompañan deben usarse como
una herramienta para manejar el riesgo en los procesos de selección.
En los análisis realizados se utilizó la información que se muestra en el siguiente
cuadro y se obtuvieron evaluaciones para 437 toros, de los cuales, 50 tienen más de 5
hijos y tuvieron por lo menos una cría entre 2010 y 2013 (son los que se presentan en
esta publicación) y 4,218 madres.

Objectives of this study were to investigate changes in predicted transmitting abilities (PTA) of yields from evaluations based on first records to evaluations based on first and later records of daughters and determine whether these changes are heritable. Data were USDA sire evaluations of July 1989 through May 2000 on Holstein bulls in standard progeny testing programs. Changes in PTA for milk, fat, and protein from evaluations based on first records of daughters to evaluations on first and second were obtained on 2001 bulls. These were divided into two sets: subset 1 (n = 889) included bulls first evaluated before 1995 and subset 2 (n = 1112) included bulls first evaluated in 1995 and later. Changes in PTA from first-record evaluation to most recent evaluation (May 2000) were obtained on 2524 bulls first evaluated in 1995 or later. Mean changes in PTA for bulls first evaluated in 1995 and later were smaller than mean changes for bulls evaluated earlier but standard deviations wer...

A procedure of sire evaluation for multiple binary responses when information is missing for some traits is described. The genetic model assumes a conceptual underlying multivariate normal distribution rendered discrete by abrupt thresholds. Statistical inferences are made from a posterior distribution consisting of several conditionally independent likelihood functions and a multivariate normal prior distribution. Each likelihood function corresponds to a particular class of information available. Point estimators and predictors of fixed and random effects are the values that maximize the posterior distribution conditionally on heritabilities and genetic correlations. The procedure involves nonlinear maximization. An example involving joint selection for calving ease and skeletal development illustrates the principles. Application of the methodology as a potential means of removing bias due to selection for categorical traits is discussed.